Process of separating mixed fibers



" UNITED STATES ATENT OFFICE.

GEORGE M. RICE, 2D, AND ALFRED L. RICE, OF \VORCESTER, MASSACHUSETTS.

PROCESS OF SEPARATING MIXEC FIBERS.

SPECIFICATION forming part of Letters Patent No. 558,111, dated April 14, 1896.

Application filed June 10,1895. Serial No. 552,322. (No specimens.)

To all whom, it may concern.-

Be it known that we, GEORGE M. RICE, 2d, and ALFRED L. RICE, citizens of the United States, residing at Worcester, in the county of WVorcester and State of Massachusetts, have invented a new and useful Improvement in the Art of Separating Mixed Fibers for the Recovery of WVool Fiber, of which the following, together with the accompanying drawings, is a specification sufficiently full, clear, and exact to enable persons skilled in the art to which this invention appertains to make and use the same.

The object of our invention is to afford, in, the art of treating mixed fibrous materials containing wool,vegetable fiber,and silk fiber, a ready and improved method for effecting in a convenient and practically efficient manner, simultaneously, the dissolution or destruction of the vegetable fiber and silk fiber for eliminatin g the same from the wool,while preserving the wool fiber in a suitable condition for reworking, as may be desired. 1

In our present method the acid which is the disintegrative chemical agent is appliedto: the stock in watery solution or liquid form, the stock being treated in wet process, for which we prepare a liquor or solution containing a percentageof free acid. The chemical agent employed may be any of the wellknown acids of commerce heretofore employed in this art, a mixture of them, or a mixture of ingredients capable of affording free acid by chemical action. We prefer, however, to employ muriatic or hydrochloric acid, as such acid leaves the product in better condition than does sulfuric or other acids when employed for the purpose, although either acid, if employed in the manner stated, will effect the removal of the vegetable and silk fibers. When hydrochloric acid is used as the chemical agent, the solution or bath is made to contain from ten to twenty-five per cent. of its weight of acid and ninety to seventy-five per cent. of water, according to the kind or condition of the wool stock under treatment, light open stock requiring a less proportion of acid than is required for dense heavy stock in any case. When sulfuric acid is used, the proportion of acid should be about five to twenty per cent. of the weight of the water employed in the solution to effect equivalent results under like conditions. In case chemical ingredients are employed which will afford free acid by decomposition-ms, for instance, chlorid of lime, bisulfate of soda, &c.-then the solution is made of a strength sufficient to afford the desired equivalent of acid in proportions substantially as above.

The mixed fibrous material, rags, or Wool stock is first immersed in the acid solutionor liquor employed and left to soak thirty minutes, more or less, or until the stock is thqroughly saturated therewith. It is then taken out and drained, or, if preferred, passed through a hydro-extractor or such proportion of the acid moisture by any suitable means expelled as may in any instance be preferre sufficient moisture being left in the stock for the generation of acidulated vapor therefrom by externally-applied heat. then, in its acidulated condition, introduced into and shut up within a tightly-closable con.- tainer, which may be of any suitable desired form or construction; but preferably we employ a rotatable cylinder having means for its ready and complete closure. The stock under treatment being confined therein, the cylinder is slowly revolved and subjected to externally-applied heat,which may be from any convenient source and of a degree sufficient to effect the desired action. The externally- The material is applied heat raises the temperature of the inclosed mass, causing a sweating or reeking action in the mass and partial vaporization of the inherent acid solution in confinedproximity to the fibers carrying such acidulated moisture, without allowing the vapor to escape from the fiber and thereby Without excessive heat effectin g the softening and dissolution of the silk fibers and vegetable fibers simultaneously, rendering them disintegrable, while the wool fiber remains practically intact.

The container or cylinder is best provided with a small vent or escape pipe, through which some of the vapor may be permitted to escape, for regulating pressure within, also to facilitate making tests as to the progress of the chemical action as the treatment is in progress. The heat is applied to the exterior until vapor is produced within the cylinder and the stock contained in it is under slight pressure from the vapor generated within the fibrous mass. It is'intended and desired to hold a part of the moisture in the material under treatment to preserve the wool in good condition. y

The heat is maintained and the mixed stock digested or sweated in the manner described for a period of about forty-five minutes, more or less, or until the desired dissolution of the silk fiber and vegetable fiber is attained. The period of time necessary to effect this result varies somewhat according to the character of the stock under treatment. The stock is then removed from the container, passed through the washing or scouring operation, and in usual manner then dried and dusted. The recovered wool is then ready to be employed for any desired purpose.

Most of the destroyed vegetable fiber is washed out in the scouring operation, together with a considerable portion of the dissolved silk substance, that part remaining being ground into dust and eliminated in the pick ing operation.

In some instances a portion of the contained moisture in the stock undergoing treatment may be distilled or driven off by leaving open the vent-pipe in the container. This may be desirable when the saturation is above twenty-five per cent. of the original weight of the stock.

\Ve do not wish to confine ourselves to the use of a container having an escape pipe or opening, as the process described can be carried out successfully in a hermeticallyclosed vessel in which the stock is maintained under pressure and digestive action by vapor generated within it by external application of heat for a sufficient length of time.

The distinctive feature of this process is the treatment of the stock in acidulated condition and while containing moisture suffi-j cient for vaporization and its subjection under close confinement within a closed conv tainer to extraneously-applied heat, thereby generating from the inherent acidulated i moisture a hot vapor and affording within the mass a sweating heat that effects digestive or disintegrating action. The acidulated vapor being confined insures positive action upon the fiber in a manner to reduce, simultaneously, the vegetable matter and the silk substance to a condition that will allow its elimination from the wool before material in jury to the wool fiber has occurred.

What we claim, and desire to secure by Letters Patent, is

1. The improvement in the art of separating mixed fibers for the recovery of wool; which consists in saturating the stock or mixed fibrous material with a watery solution containing free acid, confining such material in moist acidulated condition, within a tightlyclosable container, then inducing vaporous generation within the confined mass by extraneously-applied heat, holding such generated vapor confined upon the fibrous stock until solvent action upon the silk, and vegetable substance ensues, then removing the material from the container in wet condition, and washing out and discharging therefrom the destroyed fibrous substances, substantially as and for the purposes set forth.

The process of disintegrating silk fiber, in mixed rags or wool stock which consists in wetting the fiber-with a liquid containing free hydrochloric or other acid; inclosing the material in a close container while moist or wet; applying heat extraneously and thereby subjecting the fibrous material to the action of heat, together with acidulated moisture, and

the acidulated steam generated therefrom within the container, holding the heat and retaining the major part of the moisture upon the fiber until disintegration of the silk fiber ensues, substantially as described.

Witness our hands this 8th day of June, A. D. 1895.

GEO. M. RICE, 2D. ALFRED L. RICE.

\Vitnesses CHAS. H. BURLEIGH, ELLA P. BLENUS. 

